config wuftpd

i have installed wu-ftpd 
and read man page and FAQ 
i copy the ftpaccess file to /ete/ftpaccess

http://www.wu-ftpd.org/examples/

root@SIM:/etc# ftpwho
Service class all: 
   -   0 users ( 10 maximum)
root@SIM:/etc# ftpcount
Service class all                  -   0 users ( 10 maximum)
root@SIM:/etc# ftp 172.16.100.120
lftp 172.16.100.120:~> 
`ls' at 0 [重新连接前延时: 13]  


i can login 

what's the problem?
is there anything i should  do other than config /etc/ftpaccess?

most importantly, how can i let my ftp server work?

thank you


-- 
Your heart is pure, and your mind clear, and your soul devout.